1. Field of the Invention
The present invention relates to an optical disk recorder having a function of erasing data in an optical disk.
2. Description of the Related Art
Conventionally, an optical disc recorder has a function for formatting an optical disc further to functions for writing data into the optical disc and reproducing the data written in the optical disc. The optical disc to which data are recordable includes write-once optical discs into which the data can be written only once and rewritable optical discs into which data can be rewritten repeatedly by a predetermined times. As for the write-once optical disc, CD-R (CD Recordable), DVD-R (DVD Recordable), DVD+R (DVD Recordable) are exemplified. Furthermore, as for the rewritable optical disc, CD-RW (CD Rewritable), DVD-RW (DVD Rewritable), DVD+RW (DVD Rewritable), DVD-RAM (DVD Random Access Memory) are exemplified.
In the rewritable optical disk, new data can be overwritten over data written on the disc and the data already written on the disc can be erased. When a user erases the data written on the optical disk, a picture which renders the user to confirm execution of erasure is displayed on a monitor screen connected to the optical disk recorder to which the optical disk inserted or a personal computer which mounts the optical disc recorder. When the user selects erasure, the data written on the optical disk is erased, so that the user cannot use the erased data again. Thus, when the user erases data by mistake or persons other than the user erase data intentionally or inadvertently, the user cannot use the erased data again.
Therefore, Japanese Laid-Open Patent Publication No. 2002-197789 discloses a recording medium which stores record protection data for protecting data written on the recording medium against undesired writing or erasure in order to prevent non-availability of the data due to accidental data erasure. However, although this recording medium can prevent undesired data erasure, the user cannot use the erased data in the same way as before erasure.
Japanese Laid-Open Patent Publication No. 2003-272292 discloses a recording medium in which write control data representing whether the optical disk is in a data write inhibit state or data write enable state is written to control writing/erasure of data to/from the optical disk and based on the information, writing of data to the optical disk is controlled. However, although the recording medium can control erasure of data in the optical disk on the basis of the control data, when the user erases the data due to a wrong operation of the recording medium, the erased data cannot be used again.
Japanese Laid-Open Patent Publication No. 2004-213748 discloses an optical disk apparatus in which data is written at a location shifted from a location where data should be stored and accessed on the basis of an identification ID unique to the optical disk device to prevent that persons other than the user erase data with malicious intent and the user cannot use the data. However, in an optical disk on which data is written by the optical disk device, data is stored at the location shifted from the proper location. Thus, OS (Operating System) in other apparatuses other than this optical disc apparatus cannot recognize the data. Accordingly, although the third person cannot erase the data by using the other devices with malicious intent, when the user erases the data in the optical disk by mistake, the erased data cannot be used again.
Japanese Laid-Open Patent Publication No. 2003-059051 discloses an optical disk apparatus in which data to be written is sent again to a host system when the power cuts off during processing of writing data to an optical disk and the data writing processing is interrupted, resulting in loss of various kinds of data necessary for the data writing processing, and at restart of data writing, pseudo data writing processing is executed up to the data writing interrupt location to reconstitute the lost data. In this optical disk, when the data writing processing is interrupted, various kinds of data lost due to interruption is reconstituted. However, when the third person erases the user data in the optical disk with malicious intent, the erased data cannot be used again.
Japanese Laid-Open Patent Publication No. 2002-244753 discloses an optical disk in which installation management data is formed as a ROM or written in a recording area. A method for installing an application program forcibly executing an erasure operation with respect to a ROM area which records an install program therein in the optical disk to erase illegal copied data is also known. However, according to the installation method, although illegal data installation is prevented and data in the illegal copied optical disk is erased, when the user erases data stored in the optical disk, the data cannot be used again after the erasure processing.